This cast "Xalgoz's Draining Spirit" shortly after aggro and then again 45 seconds later. This is its mana DOT.

It also cast "Dread Admiral's Curse" right after it was aggro'd and then again 65 seconds later. This is a single-target viral DOT and a nasty one at that. The time before it goes viral appears to be 10-12 seconds, and it hits anyone within 200'. Lasts 8 ticks. No counters.